24 DiuSiioiis for Tanning 



and comprelTing them, than from the thick hides, which 

 when Hmed are harfli and apt to crack, if the lime is not to- 

 tally extradled before they are tanned. 



Aniongd the different modes of immerfion, which may be 

 praftifcd m the courfe of thefe operations, the beft way feems 

 to be that of fufpending the hides and (kins vertically in the 

 Jixivja, by means of tranfverfal rods or bars, and at fuch a 

 diftance afunder as not to touch each other in anyone point. 

 If they are laid out one over the other, according to the com- 

 mon praftice, they will require frequent handling, in order 

 that all the parts may be equally faturated, and (o prevent 

 the folds or pljiits that would otherwife be formed in them ; 

 all this would occafion a confiderable lofs of time and labour. 



In fome cafes it will be found expedient to mix frefh tan 

 from time to tim€ with the lixivium ; this and other modi- 

 fications, fuch as the various ftrengths of the lixivium, the 

 raifing or not railing the hides, the ufe of the gallic Hxivium, 

 &c., which may be found neceflary, will depend on the ftate 

 and quality of the hides and fkins to be tanned, as well as oa 

 the pnrpofes for which they are intended : all thefe confider- 

 ations muft be left to the judgment of the manufafturer, but 

 do not in any way alter or change the principle on which 

 this mode of thinning is founded. 



Befides the very great favings in point of time and labour, 

 the leather tanned according to the above method, being 

 more completely faturated, will be found to v^'cigh heavier, 

 to wear better, and to be lefs fufceptible of moifture, than the 

 leather tanned in the ufual way, 



THE following additional explanations may be of ufe to 

 thofe to whom fcientific terms and chemical operations are 

 not familiar. 



1. Eefpe6ling the number, the difpofition, and the dl- 

 menfions of the digefters, Five or fix of thefe veflcls are fuf- 

 iicient to fhav/, by way of experiment, the nature of the 

 proccfs, the dilTerent principles contained in the bark, hovv 

 they i^re to be ditlinguifhed and feparated from each other. 

 Sec. But when the bufinefs is conduced on a permanent 

 and extenfive fcale, a much greater number will be neceflary, 

 not only for the purpofe of fupplying the required quantity 

 ot liquor, hut alfo for fpending or completely exhauitmg the 

 tan, particularly in cold weather, or if hard water is ufed, 

 and the bark not ground fine enough. I would recommend 

 (welve digefters at Icaft, fully to anfwer thefe purpofes. 



They may be difpofcd in four rows of three veflcls each : the 

 two( nii^ldlc rows placed clofe to each otherj the two fide rows. 



feparated 



